If the difference in speed is small, i say drop the
arrays and use hashes ... but i am lazy. I have this
adversion to something called 'typing'. ;)

But, arrays are not always faster than hashes. It all
depends upon context - if you have to scan the entire
array to find something, a hash implementation will
probably be faster. But if you have to iterate over all
elements - then an array is probably the better choice.
Consider the following Benchmark code: